[unreadable] [unreadable] Green fluorescent protein from Aequoria victoria (GFP) has revolutionized cellular bioimaging studies. GFP has been used in viruses, bacteria, cultured cells, yeast, transgenic plants, and transgenic animals from worms to mice. The utility of GFP has stimulated numerous mutational studies to enhance the usefulness of GFP as well as attempts to explore fluorescent proteins from species other than Aequoria. The available repertoire of fluorescent proteins remains limited for many bioimaging applications. By far, the greatest diversity of marine life harboring fluorescence exists on the Great Barrier Reef, located off the eastern coast of Australia. We recently embarked on an expedition to collect fluorescent marine specimens from this region of the world. About a hundred specimens have been collected and partially characterized, and we have cloned the first novel fluorescent protein from coral derived from the Great Barrier Reef. We are applying in response to the Request for Applications (RFA: EB-03-003) "Research and Development of Systems and Methods for Cellular and Molecular Imaging", to continue this work, and to clone and characterize novel fluorescent proteins for use as tools in bioimaging research. Our objectives are to: (1) Construct and screen cDNA libraries for novel fluorescent proteins from marine organisms collected from the Great Barrier Reef; and (2) Characterize cloned, recombinant fluorescent proteins with respect to: (a) spectral properties; (b) chemical stability; (c) expression in bacteria and cultured mammalian cells; (d) expression in a prototypic small animal, Xenopus laevis. There is currently a great need for such new tools, and it is expected that the new fluorescent proteins characterized from this project will find wide applicability in many branches of medicine and biology. [unreadable] [unreadable]